1. Field of the Invention
The disclosed embodiments relate generally to information storage. More particularly, the disclosed embodiments relate to maintaining consistent references across differing versions of a collection of data.
2. Description of Related Art
In a large collection of information about objects, it is frequently desirable to collect new information on an ongoing basis. When new information is collected, the new information sometimes supplements or supersedes information already stored in the information collection. To facilitate the effective retrieval of information, object identifiers are used to refer to particular objects in the collection of information. Ideally, an object identifier can be used to retrieve all of the information associated with an object regardless of when or how that information was originally collected.
Assigning a new object identifier to newly collected information results in an object identifier persistence problem when the newly collected information describes an object already in the collection. If the old object identifier is used to retrieve the information about an object, the newly collected information will not be retrieved, as the newly collected information is only associated with the new object identifier. Thus, the old object identifier fails to persist—that is, the old object identifier cannot be relied upon to accurately and completely retrieve all the available information related to its corresponding object.
Therefore, what is needed is a method for making identifiers persistent while incorporating new information into a collection.